Kephir is another form of fermented milk, resembling koumiss. It is made from cow's milk - alcohol, lactic acid, and albumin being formed as a result of the fermentative process. The casein is partly digested. Tablets of the kephir ferment are sold for the home manufacture of the milk; it may also be made as follows: -

Boil fresh milk, and when nearly cold put into quart bottles, leaving room to shake. Add half an ounce of crushed lump sugar and a piece of Vienna yeast the size of a hazel nut (i.e. 20 grammes), cork with new corks, tic down, keep cool; lay the bottles horizontal, but shake twice daily. It will be ready to drink about the sixth day, or earlier in hot weather and later in cold weather. It can be made with skimmed milk (see also p. 540 .